Re: the parsing of parameters

Neil Conway <nconway(at)klamath(dot)dyndns(dot)org> writes:
> nconway=> prepare q2 as select $1;
> ERROR: Parameter '$1' is out of range

> (You'll see the same parse error with simply "select $1;")

You need to tell the parser the number of parameters to expect and their
datatypes. This is what the last two arguments to parser() are all
about. Look at _SPI_prepare for an example (I think plpgsql uses that).
Also, the plpgsql code for parameterized cursors might be a helpful
reference.

The actual syntax of PREPARE probably has to be something like

PREPARE queryname(parameter type list) FROM query

else you'll not have any way to get the type info.

> BTW, is this a legacy from postquel? (from include/nodes/primnodes.h)

I don't believe anything is using named parameters presently. PARAM_NEW
and PARAM_OLD also seem to be leftovers from an old implementation of
rules.

regards, tom lane